Device and method for inspecting crankshaft journals



J. A. HALGREN Aug. 1, 1961 DEVICE AND METHOD FOR INSPECTING CRANKSHAFT JOURNALS Filed March 10, 1959 United States Patent 2,994,220 DEVICE AND METHOD FOR INSPECTING CRANKSHAFT JOURNALS John A. Halgren, Downers Grove, 11]., assignor to International Harvester Company, Chicago, 11]., a corporation of New Jersey Filed Mar. 10, 1959, Ser. No. 798,495 4 Claims. (Cl. 73105) This invention relates to an improved method and apparatus for permitting the inspection of journals of crankshafts and the like. More specifically, this invention relates to an improvement in the method and apparatus for determining the surface finish in friction type bearings.

It is a prime object of this invention to provide an improved method and device for inspecting the surface finish of friction type bearings.

Still a further object is to provide an improved method for quickly inspecting surface flaws in cylindrical objects, the said method being inexpensive, rapid, and easily accomplished.

A still further object is the provision of an improved apparatus of simplified construction which can be utilized in the inspection of crankshaft journals in locations distant from the factory such as service stations, field repair shops, etc.

Still a further object is the provision of an improved inspection method for quickly inspecting surface flaws which may be found in friction type bearings, the said method being easily applied and resulting in a test which can easily be compared to predetermined standards.

These and other objects will become more readily apparent from a reading of the description when examined in connection with the accompanying sheet of drawing.

In the drawing:

FIGURE 1 is a side elevational view showing a conventional crankshaft and an apparatus for inspecting the surfaces of the journal portions;

FIGURE 2 is a cross sectional view taken substantially along the line 22 of FIGURE -1; and

FIGURE 3 is an enlarged perspective view of a strip portion used in an inspection procedure.

Referring now particularly to FIGURE 1, an apparatus for inspecting surface flaws is generally designated by the reference character 10. The apparatus is shown in operative position in connection with a crankshaft 11, the said crankshaft 11 being conventional and including bearing portions 12 suitably connected to cylindrical journal portions 13 by means of counterweights or checks 14.

Referring now particularly to FIGURE 2, the apparatus 10 includes a housing 15 having an upper Wall 16 and a lower wall 17. The housing 15 includes an opening 18 provided in the lower wall '17 and a supporting member 19 is supported between laterally spaced side walls 17 at the forward end of the housing 15. The supporting member 19 includes at its forward end a curved portion having a conforming face 18', the forward end of which is supported immediately adjacent a front wall 1 9' of the housing 15. A roll 20 is supported for rotation on a shaft 21 within the housing .15. The roll 20 has provided thereon a roll of strip tape 22 having a strip portion 23 engaging and being supported on the underneath surface of the supporting member 19. An end of the strip portion 23 is connected at its extremity to the front wall 19 by means of an attaching clip 24 suitably tightened to the front wall 19 by means of a screw 25.

The upper wall 16 at the forward end of the housing 15 supports a weight holder 26 having positioned therein a weight 27. One end of the housing 15 includes a sliding support 28 which is adapted to reciprocate on a table support 29' 2,994,220 Patented Aug. 1, 1961 Referring to FIGURE 3, the strip tape is indicated as having a plurality of scratches or indentations 30 which result during the inspection of the journals 13.

The crankshaft 11, as best shown in FIGURE 1, is

mounted for rotation on a spindle 31 suitably engaging The strip tape 22 consists of a material having thecharcteristics of receiving an impreession in response to projections or indentations in the surface of the crankshaft journals 13. It has been found that metal or plastic foil is particularly well suited. One example having the desirable characteristics, for instance, would be aluminum foil of any conventional type on the market. The material can be of any type which will readily be subject to scratching during the inspection operation. Thus the strip should be of a suitable width, thickness and hardness to achieve these desirable characteristics.

In the inspection procedure, one or more of the apparatus 10 is associated with the crankshaft journals as shown in FIGURES 1 and 2. The housing 15 may-be suitably supported for sliding movement on the support tables 29. Upon operation of the electric motor 33, the crankshaft 12 is rotated causing rotation of the journals 13. Each journal 13 may have an apparatus 10 associated therewith as shown in FIGURE 2 wherein the strip portion 23 is in surface contact with the outer peripheral surface of each journal 13. The weight 27 urges the end of the housing 15 downwardly so that pressure is applied against the end of the strip 23 so that the said strip is in partial conformance around portions of the periphery of the outer surface of the journal 13, the said strip also being in surface contct with the conforming face 18. Thus as the journals 13 are rotated any indentations or projections on said surface which denote surface imperfections, scratch or become embossed on the sensitive surface of the strip 23. As shown in FIGURE 3, such scratches 30 result from the surface imperfections which any particular journal 13 might contain. The support 19 may consist of sheet metal or may consist of a suitable resilient material such as rubber. The weight 27 may be varied so that heavier or lighter pressures may be applied at the front end of the housing 15 depending on the type of strip material which is utilized. As the crankshaft thus is rotating, the housing 15 will reciprocate on the table 29.

After the crankshaft has been rotated a suitable number of times, the strip end 23 is severed from the remainder of the roll 22 and the scratches 30 may be compared with a suitable standard. Such a standard may consist of a sample plate having one or more scratches of certain length, the said sample having previously been determined to either be satisfactory or unsatisfactory. Thus if, for instance, the standard sample indicates that a similar result is satisfactory, the inspector can examine the strip 30 in connection with the sample and by visual comparison decide whether or not the crankshaft journal imperfections are of such a nature as to be within the standards set.

Thus it is apparent that a very simple method of inspection of crankshaft journals and the like has been disclosed. Also it is readily apparent that the apparatus is of a simplified design so that surface inspection can be carried out in a quick and economic manner. Thus the objects of the invention have been fully achieved and it must be understood that modifications and changes may be made in the method and apparatus which do not depart from the spirit of the invention, as disclosed, or the scope thereof as defined in the appended claims,

What is claimed is:

1. Apparatus for inspecting surface irregularities in a rotatable cylindrical object having an outer peripheral surface comprising, means supporting said cylindrical object for rotation about its axis, means for rotating said object, a holder movably positioned relative to said object, said holder including a curved supporting face conforming partially to the surface of said cylindrical object, a strip dispenser supported on said holder, a strip material on said dispenser, said strip material having a portion in position adjacent said supporting face, and means applying pressure to said holder to move the same whereby said strip portion is forced in surface contact with said supporting face and said outer peripheral surface, said strip material during rotation of said object having characteristics which adapt the same to receive impressions resulting from indentations and projections in said peripheral surface.

2. Apparatus for inspecting surface irregularities in a rotatable cylindrical object having an outer peripheral surface comprising, means supporting said cylindrical object for rotation about its axis, means for rotating said object, a holder movably positioned relative to said object, said holder including a supporting face complementing a port-ion of the surface of said cylindrical object, a strip dispenser supported on said holder, a strip material on said dispenser, said strip material having a portion in position adjacent said supporting face, and means applying pressure to said holder to move the same whereby said strip portion is forced in surface contact with said supporting face and said outer peripheral surface, said strip material during rotation of said object having characteristics which adapt the same to receive impressions resulting from indentations and projections in said peripheral surface.

3|. Apparatus for inspecting surface irregularities in a rotatable cylindrical object having an outer peripheral surface comprising, means supporting said cylindrical object for rotation about its axis, means for rotating said object, a holder movably positioned relative to said object, said holder including a curved supporting face conforming partially to the surface of said cylindrical object, a strip supported on said holder, said strip having a portion in position adjacent said supporting face, and means applying pressure to said holder to move the same whereby said strip portion is forced in surface contact with said supporting face and said outer peripheral surface, said strip material during rotation of said object having characteristics which adapt the same to receive impressions resulting from indentations and projections in said peripheral surface.

4. Apparatus for inspecting surface irregularities in a rotatable object having an outer surface comprising, means supporting said object for rotation about its axis, means for rotating said object, a holder adapted to be positioned adjacent to said object and being movable toward said object, said holder including a supporting face conforming to the surface of said object, an impression receiving element supported on the supporting surface of said holder, and means applying pressure to said holder to move the same whereby said element is forced in surface contact with said surface of said object, said element during rotation of said object having characteristics which adapt the same to receive impressions resulting from indentations and projections in said surface of said object.

References Cited in the file of this patent UNITED STATES PATENTS Richards Aug. 1, 1939 Kowalski Mar. 25, 1941 OTHER REFERENCES 

